1. Field of the Invention
This invention lies in the field of communication systems and, more particularly, combined intercom and radio systems for aircraft use.
2. Description of the Prior Art
Present day aircraft operation relies increasingly upon flexible radio communication systems, for communication with external locations, such as ground stations, and for internal communication, as between pilot and co-pilot, instructor and student, and pilot and passengers. A wide variety of radio system components are commercially available, as are intercom systems, and there is no problem in finding adequate components for desired aircraft radio/intercom systems. In fact, the problem is not in the availability of the desired radio components, but in the proper integration of all of the desired radio and intercom channels, so as to make available the desired flexibility of channels with a minimum number of operator controls. For example, there is a great need for efficient equipment for processing a plurality of microphone inputs so that they are available both for external radio transmission and intercom transmission, for processing received inputs for both pilot and intercom reception, and providing for efficient operation by pilot, co-pilot and passengers of the integrated system so as to make available the desired and intercom audio signals.